Grinding Wheel Assembly for Facilitating Attachment and Detachment of a Grinding Tool

ABSTRACT

The present invention relates to a grinding wheel assembly usable in a polishing machine for finishing a surface or floor, and more particularly, to a grinding wheel assembly for facilitating attachment and detachment of a grinding tool, capable of preventing damage to the grinding tool caused by centrifugal and frictional force produced by high speed rotation, and which reduces working time and enables convenient use due to easy replacement of the grinding tool. The grinding wheel assembly includes a ferromagnetic grinding tool, and a disk-shaped grinding wheel including a tool mounting part with a recess shape sized for mounting the grinding tool and a magnet embedded in one side. When required, a protruding separation prevention pin is provided to stably mount the grinding to the tool mounting part and a push injector pin is provided to facilitate attachment and detachment of the grinding tool.

CLAIM TO FOREIGN PRIORITY

The present application is a U.S. National Stage Application filed under 35 U.S.C. 371 claiming priority from International Application No. PCT/KR2010/007129, filed Oct. 18, 2010, which claims the benefit of priority of Korean Application No. 10-2009-0123699, filed on Dec. 14, 2009, which applications are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a grinding wheel assembly provided in a polishing machine for finishing a surface or a floor of concrete/asphalt and structure, and more particularly, to a grinding wheel assembly for facilitating attachment and detachment of a grinding tool and capable of preventing damage of the grinding tool caused by centrifugal force and frictional force produced by high speed rotation, reducing working time, and allowing convenient utilization of the grinding wheel assembly due to ease of replacement of the grinding tool.

BACKGROUND OF THE INVENTION

In general, the surfaces of various interior and exterior ornamental materials for a building, including stone material such as concrete and marble, are formed in a predetermined shape and then subjected to a finish process for removing fine protrusions and cracks remaining on the surfaces to improve salability and use convenience thereof. In the finish process, a polishing machine provided with a grinding tool on the lower part is used to perform a polishing or gloss treatment by rotating the grinding tool at a high speed.

In other words, referring to FIG. 1, grinding unit 102 to be rotated at a high speed by a rotation force from driving unit 101 is provided at a lower part of polishing machine 100. In grinding unit 102, a polishing or gloss treatment is performed through grinding tool 120 provided at grinding wheel assembly 110 that is rotated on a rotation axis.

Generally, grinding tool 120 for a polishing operation is made by mixing, forming and then sintering diamond powder with metal powder such as iron, tungsten, or cobalt powder. Grinding tool 120 may be fabricated variably depending on operation conditions of the concrete or marble to be polishing and the gloss treatment.

The grinding tool may be worn away rapidly depending on the operation time period and operation circumstances and further damaged due to cracks formed while it is operating, and thus needs to be replaced.

Accordingly, a configuration of grinding tool 120 must be installed easily and promptly to grinding wheel assembly 110 and further must not to be damaged due to friction force and centrifugal force while it is rotated at a high speed and must not become separated from the grinding wheel assembly.

According to the prior art the grinding tool has been welded and attached directly to the grinding wheel assembly.

However, referring to the method for attaching the grinding tool to the grinding wheel assembly using welding, when the grinding wheel assembly is used for a long period of time and the grinding tool is worn away, the grinding tool cannot be separately replaced, and thus the whole grinding wheel assembly has to be replaced which increases the component cost. Specifically, among the plural components for constituting the grinding wheel assembly, even if only part of the components are failed or damaged, the whole grinding wheel assembly has to be replaced thereby uneconomically wasting material and delaying the work schedule due to the replacement.

In order to solve the drawbacks as described above, grinding wheel assembly 110 in which grinding tool 120 can be easily replaced has been studied, and prior grinding wheel assemblies will be described referring to FIGS. 2-5.

As shown FIG. 2( a), according to a prior art, grinding tool 120 has been attached to grinding wheel assembly 110 by using a plurality of bolts 121. However, according to the prior art the plurality bolts have to be fastened and unfastened whenever the grinding tool is replaced, thereby making the time period of the installment procedure be long. In particular, there is still a problem in that grinding tool 120 is disengaged from the grinding wheel assembly due to a breakdown of the bolt.

Further, as shown in FIG. 2( b), a technology has been proposed of attaching the grinding tool to the grinding wheel assembly wherein supporting piece 122 protruding from both sides of a bottom surface of grinding tool 120 is formed and supporting piece connection recess 112 a is formed on grinding wheel assembly 110 and adapted for the insertion of supporting piece 122 of grinding tool 120.

Alternatively, as shown in FIG. 3 and in contrast to FIG. 2( b), fixing recess 123 is formed on a bottom surface of grinding tool 120 and fixing protrusion 112 c adapted to be forcibly fitted into fixing recess 123 is formed in grinding wheel assembly 110.

The widths of supporting piece connection recess 112 a and the fixing recess 123 decrease gradually inwardly for the supporting piece and the fixing protrusion to be guided so as to be fixed easily thereto.

However, according to the method for fixing grinding tool 120 using a dovetail configuration as described above, additional work for firmly fixing grinding tool 120 to grinding wheel assembly 110 according to a forcible fitness of the recess and the protrusion is required such that the protrusion is struck by a separate installment device such as hammer H.

As a result, a crack is produced while the protrusion is driven into the recess and thus the structure to be supported such as the supporting piece is shaped as protrusions 122 or 112 c and breaks down while the grinding operation is performed, thereby damaging the grinding tool 120.

In addition, the bonding force between the grinding tool and the grinding wheel assembly increased by using Velcro (112 b in FIG. 2) when required, however, using Velcro is not very helpful when grinding a coarse concrete surface.

In FIGS. 4 and 5, unlike the configurations shown in FIGS. 2 and 3, a technology has been tried for increasing the connection force between the grinding tool 120 and the grinding wheel assembly 110 while improving operation efficiency, but which still needs additional fixing work performed externally by using an installment device such as hammer H in order that the grinding tool 120 will not be broken and pulled out while operating, due to the connection configuration of the connection recess 112 a and the supporting piece protrusion 122 which firmly fix the grinding tool to the grinding wheel assembly.

Furthermore, as not shown in drawings, a wedge-bit has been fitted between the protrusions of the grinding tool 120 and the grinding wheel assembly 110 to fix the grinding tool 120, however, the wedge-bit still required an additional separate installment device such as hammer H.

As described above, in the prior grinding wheel assembly 110 a separate installment device is required to replace the grinding tool 120 while it is operating, thereby delaying the replacement time period and making it difficult for a beginner to replace the grinding tool. Further, the fixing device configured as the recess and protrusion types is damaged including crack production and breaks down while a high speed rotation grinding operation is performed.

As a result, there essentially needs a grinding wheel assembly in which grinding tool 120 does not break down during high speed rotation grinding and in which the grinding tool 120 can be easily installed and replaced.

SUMMARY OF THE INVENTION

The present invention has been proposed, and an object of the present invention relates to provide a grinding wheel assembly for facilitating the attachment and detachment of a grinding tool through which the grinding tool is not damaged during mounting and not disengaged during grinding operations while permitting the grinding tool to be mounted easily and quickly.

Furthermore, another object of the present invention relates to providing a grinding wheel assembly for facilitating attachment and detachment of a grinding tool in which the attachment and detachment of the grinding tool is easily performed by using a magnet and ferromagnetic grinding tool, providing a tool mounting part to which the grinding tool is mounted wherein a separation prevention pin is provided in one side of the tool mounting part for fixing the grinding tool and thus the grinding tool is not broken down or separated by centrifugal force, frictional force or the weight of the polishing machine while a grinding operation is performed.

In addition, still another object of the present invention relates to provide a grinding wheel assembly for facilitating attachment and detachment of a grinding tool in which a push injector pin and a recess for pushing configured to push and raise the grinding tool, when required, are provided in order to easily separate the grinding tool fixed by a magnet.

According to an aspect of the present invention, a grinding wheel assembly is provided, mounted to a grinding part of a polishing machine, and performs a grinding operation, which facilitates attachment and detachment of a grinding tool, the grinding wheel assembly comprising a ferromagnetic grinding tool and a grinding wheel having a disk shape. The grinding wheel includes a tool mounting part shaped as a recess sized for mounting the grinding tool and into which a magnet is embedded in one side of the inner surface.

The grinding tool includes a steel plate provided with at least one pin through holes in one side thereof and sized to be mounted in the tool mounting part, and a grinding tip fixed protrudingly over the steel plate. The tool mounting part further comprises protruding separation prevention pins corresponding in number and location of the pin through holes.

The grinding wheel is further provided with, when required, a concave shaped recess for pushing on the end of the grinding tool mounted along the outer peripheral surface corresponding to the tool mounting part. The concave shaped recess assists in raising the end surface of the grinding tool and easily separating the grinding tool from the magnet.

Furthermore, the tool mounting part further includes, when required, a push injector pin that passes through the grinding wheel in order to push the bottom surface of the grinding tool mounted in the tool mounting part and separate the grounding wheel from the magnet.

The grinding wheel includes a mounting wheel plate that is fixed to the grinding part and a replacement wheel plate which is sized to be in face-contact with one surface of the mounting wheel plate and mounted thereon, is attachable and detachable by a locking device, and in which the tool mounting part is formed.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view showing a polishing machine provided with a grinding tool for grinding operation;

FIGS. 2 and 3 are perspective views showing a grinding wheel assembly according to a prior art, respectively;

FIGS. 4 and 5 are views showing another grinding wheel assembly according to a prior art, respectively;

FIG. 6 is a view showing schematically a grinding wheel assembly in which a grinding tool is attached and detached easily thereto according to the present invention;

FIG. 7 is a perspective view showing a grinding wheel assembly in which a grinding tool is attached and detached easily thereto according to the present invention;

FIG. 8 is an exploded perspective view showing the grinding wheel assembly shown in FIG. 7;

FIG. 9 is a cross-sectional view showing the grinding wheel assembly as shown in FIG. 7;

FIG. 10 is a main component cross-sectional view showing an attachment and detachment of the grinding tool of the grinding wheel assembly as shown in FIG. 7;

FIGS. 11 and 12 are views showing a locking device of the grinding wheel assembly in which the grinding tool is attached and detached easily according to the present invention, respectively; and

FIG. 13 is a view showing a replaceable grinding tool according to the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals in the drawings denote like elements, and thus their description will be omitted.

FIG. 6 is a view showing schematically a grinding wheel assembly in which a grinding tool is attached and detached easily thereto according to the present invention.

As shown in FIG. 6, grinding wheel assembly 1 in which grinding tool 30 is attached and detached easily thereto according to the present invention is characterized in that grinding tool 30 is not disengaged from the grinding wheel assembly 1 and not broken down due to friction force from a work surface, centrifugal force, and the weight of the polishing machine even while grinding tool 30 is rotated at a high speed for grinding operation, and further the grinding tool can be attached and detached easily and thus replaced easily.

Grinding wheel assembly 1 in which the grinding tool is attached and detached easily thereto, provided in a grinding unit of a polishing machine for performing a grinding operation, according to an embodiment of the present invention mainly includes ferromagnetic grinding tool 30 and grinding wheel 1 a (shown in FIG. 8 and comprising wheel plate 10 and replacement wheel plate 20) having tool mounting part 2 to which grinding tool 30 is fixed by magnet 21.

Tool mounting part 2 is provided at a predetermined interval on grinding wheel 1 a, corresponding to the number of grinding tools 30. Preferably tool mounting part 2 may be a recess adapted for mounting grinding tool 30 and in one side of the inner part of which magnet 21 is embedded.

Furthermore, a plurality of tool mounting parts 2 may be provided depending on the number of grinding tools 30 to be mounted therein or the part to be connected.

Additionally, grinding wheel 1 a may have a disk shape so as to be rotated easily at a high speed during a grinding operation of the polishing machine.

A plurality of grinding tools 30 may be provided when required. Grinding tip 31 of grinding tool 30, which during a grinding operation is in contact with the surface being ground of the material being ground and is seriously abraded, is made by mixing diamond powder with metal powder such as iron, tungsten, cobalt or the like as a bonding agent and formed and then sintered. Grinding tip 31 of grinding tool 30 performs the grinding operation or the gloss operation, depending on the operation circumstances of concrete, marble or the like.

Grinding tool 30 as set forth above may be replaced by another grinding tool, when required, for performing a separate gloss operation at a low rotation speed, which will be described in detail below.

As set forth above, grinding tool 30 is fixed and mounted to the grinding wheel assembly by magnet 21 provided on tool mounting part 2 of grinding wheel 1 a. Grinding tool 30 is not disengaged outside and is kept in place by the inner wall side of tool mounting part 2 even while the grinding wheel assembly is rotated at high speed for grinding operation.

To these ends, a trapezoid-shape recess may be formed in tool mounting part 2 and grinding tool 30 may be shaped to be included and mounted in tool mounting part 2 so that the location of grinding tool 30 is fixed by magnet 21.

Furthermore, a plurality of separation prevention pins 22 that pass through one side of grinding tool 30 and are shaped as a protrusion may be provided in tool mounting part 2 in order that the grinding tool does not disengage and is fixed in place.

In more detail, grinding tool 30 is formed with at least one pin through hole 32 on one side thereof, and includes ferromagnetic steel plate 33, adapted for mounting in tool mounting part 2, and grinding tip 31 that is fixed protrudingly on an upper part of steel plate 33.

Further, separation prevention pins 22 are formed in tool mounting part 2 is such number and location as correspond to pin through hole 32 of grinding tool 30.

As set forth above, while the grinding operation is performed, grinding tool 30 is prevented from disengaging by magnet 21 provided in tool mounting part 2 and further prevented from disengaging by separation prevention pin 22 disposed passing through grinding tool 30.

Grinding tool 30 tends to be pushed to the outside of grinding wheel 1 a due to the centrifugal force produced in a radial direction as the grinding tool rotates at high speed while the grinding operation is performed, and further tends to be disengaged due to friction resistance of a heavy load from the ground.

In order to prevent this phenomenon, magnet 21 and separation prevention pin 22 are provided, and further a tool supporting protrusion 23 is formed in the inner wall end forming tool mounting part 2 to enclose the outer part of mounted grinding tool 30.

In more detail, supporting protrusion 23 serves as a support for mounted grinding tool 30 and it protrudes in a hook form inwardly at both ends of the inner wall of tool mounting part 2 so that the end of grinding tool 30 that tends to protrude and be disengaged due to centrifugal force is blocked thus stably disposing the grinding tool. As a result, external separation of grinding tool 30 can be avoided.

Fine gap a is formed between the inner wall side of tool mounting part 2 and grinding tool 30 mounted on tool mounting part 2, as shown in FIG. 6. Here, the fine gap has a size of 0.2-0.3 mm in both directions, and preferably has a size of 0.25 mm for easy attachment and detachment of grinding tool 30.

Referring again to FIG. 6, grinding wheel assembly 1 according to the present invention may have various embodiments through which the grinding tool 30 is easily attached and detached.

As an exemplary embodiment, shown in FIG. 6(A), concave recess for pushing 3 is further formed in the grinding wheel 1 a such that the end of grinding tool 30 protrudes along the outer peripheral surface corresponding to tool mounting part 2 in order that the end surface of mounted grinding tool 30 can be raised by hand to disengage grinding tool 30 from magnet 21.

That is, the end surface of grinding tool 30 that protrudes over recess for pushing 3 is pushed and raised using recess for pushing 3 when grinding tool 30 must be replaced so that grinding tool 30 is replaced easily with finger F using a small force.

Meanwhile, as shown in FIG. 6(B), push ejector pin 4 passing through grinding wheel 1 a is further provided in order to more easily disengage grinding tool 30.

In more detail, push injector pin 4 passing through grinding wheel 1 a is further provided in tool mounting part 2 to push the bottom surface of mounted grinding tool 30 and disengage grinding tool 30 from magnet 21. When the lower end of push injector pin 4 is pushed, push bar 4 b of FIG. 8 is raised by spring 4 a of FIG. 8 provided in push injector pin 4 to push the bottom surface of grinding tool 30 and disengage it from tool mounting part 2.

A plurality of push injector pins 4 may be provided in the grinding wheel assembly, depending on the numbers of grinding tool 30 and tool mounting part 2. When the push injector pin is provided in the grinding wheel 1 a, a double nut is fastened thereto in order to prevent release. As a result, the grinding tool cannot be released even in the case of frequent impacts. In addition, bellows rubber cap 4-1 of FIG. 7 is provided around the spring in order to prevent external dust from entering therein.

In more detail, referring to FIG. 8, push injector pin 4 includes push bar 4 b that passes through grinding wheel 1 a and is movable, spring 4 a that surrounds apart of the push bar protruded to the lower part of grinding wheel 1 a and applies elastic force thereto, and injector pin fixing screw 4 c for fixing the push bar to the location where the push bar passes through grinding wheel la.

Meanwhile, recess for pushing 3 and push injector pin 4 may be modified when required to enable easy attaching and detaching of the grinding tool and may be provided separately or simultaneously as shown in FIG. 6(C) to enable grinding tool 30 to be replaced easily.

In one embodiment, the bottom surface of ferromagnetic grinding tool 30 mounted on tool mounting part 2 is not in direct contact with magnet 21 embedded in tool mounting part 2.

To this end, magnet 21 is embedded in the tool mounting part with fine gap b from the bottom surface of tool mounting part 2. Since magnet 21 is not directly in face-contact with the bottom surface of grinding tool 30, the friction resistance and impact which may be produced while the grinding operation is performed is prevented, thereby increasing efficiency of magnet 21 and increasing component life to improve operation efficiency.

Preferably, referring to FIG. 6, magnet fixing bolt 21-1 for fixing magnet 21 is provided wherein the top surface of magnet fixing bolt 21-1 becomes magnetic through the magnet and minimally face-contacts the bottom surface of grinding tool 30.

FIG. 7 is a perspective view showing a grinding wheel assembly in which a grinding tool is attached and detached easily thereto according to the present invention. FIG. 8 is an exploded perspective view showing the grinding wheel assembly shown in FIG. 7. FIG. 9 is a cross-sectional view showing the grinding wheel assembly as shown in FIG. 7. FIG. 10 is a main component cross-sectional view showing an attachment and detachment of the grinding tool of the grinding wheel assembly as shown in FIG. 7. FIGS. 11 and 12 are views showing a locking device of the grinding wheel assembly in which the grinding tool is attached and detached easily according to the present invention, respectively.

As shown in the drawings, referring to FIGS. 7-11, grinding wheel assembly 1 for facilitating attachment and detachment of the grinding tool will be described as followings.

Grinding wheel assembly 1 according to the present invention is characterized in that tool mounting part 2 is formed, on which the grinding tool is mounted, so that grinding tool 30 can be attached and detached easily. Grinding tool 30 mounted on tool mounting part 2 is prevented from falling out by magnet 21 and prevented from disengaging by separation prevention pin 22 while the grinding operation is performed.

Furthermore, it is characterized in that grinding tool 30 is replaced more easily by using recess for pushing 3 and push injector pin 4, when required.

As a result, operation efficiency of the grinding wheel assembly 1 in which the grinding tool is attached and detached easily is maximized, comparing to a prior art, such that mounted grinding tool 30 does not disengage easily and break down during operation, but grinding tool 30 is replaced easily and rapidly.

Grinding wheel assembly 1 has to be easily manufactured and processed while performing the basic functions as set forth above, and preferably, grinding wheel 1 a includes mounting wheel plate 10 that is fixed to a grinding unit of a polishing machine, and replacement wheel plate 20 which is attachable and detachable to mounting wheel plate 10 and on which tool mounting part 2 on which grinding tool 30 is mounted is formed.

Replacement wheel plate 20 is connected attachably and detachably to locking device 5 and sized to be in face-contact with one face of mounting wheel plate 10 and mounted thereon.

In more detail, referring to FIGS. 7-9, in grinding wheel assembly 1 according to the present invention, mounting wheel plate 10 is a disk-shaped plate wherein holding protrusion 11 is fixed protruding upward to a middle part thereof by fixing bolt 11 a and catching pin fixing hole 11 b formed on a top surface of the holding protrusion. Further, locking device fixing hole 11 c is provided on a middle part of the holding protrusion, into which the locking device 5 is fixed and located even while it can be rotated.

Meanwhile, replacement wheel plate 20 comprises 3 disk-shape plates and is configured to be fixed to and disengaged from mounting wheel plate 10 by locking device 5.

Replacement wheel plate 20 includes replacement base plate 20-1 facing mounting wheel plate 10, magnet fixing plate 20-2 to be fixed to replacement base plate 20-1, and tool guide plate 20-2 which is fixed to magnet fixing plate 20-2 and on which tool mounting part 2 to which the grinding tool is mounted is formed.

In more detail, replacement base plate 20-1 is a disk-shaped plate provided with middle hole 20-1 a through which holding protrusion 11 of mounting wheel plate 10 passes. Pin recess 20-11 on which a lower part of separation prevention pin 22 is located is formed on one side of replacement base plate 20-1 while facing one face of the mounting wheel plate and mounted thereon.

Replacement base plate 20-1 is configured to serve as a base plate for magnet fixing plate 20-2 that is mounted thereon and tool guide plate 20-3 that is fastened and fixed thereto wherein those plates are assembled and disassembled easily by using separation prevention pin 22 and location setting pin 40 a.

Meanwhile, magnet 21 is embedded in magnet fixing plate 20-2 for fixing grinding tool 30 mounted on tool mounting part 2, and the magnet fixing plate has a disk-shaped plate with middle hole 20-2 a through which the upper part of holding protrusion 11 passing through the replacement base plate 20-1 passes and is faced to one surface and mounted on the replacement base plate. Magnet fixing plate 20-2 further includes magnet recess 20-21 in which magnet 21 is embedded and pin recess 20-22 through which the upper part of separation prevention pin 22 passing through recess 20-11 of the replacement base plate passes and is protruded, wherein magnet recess 20-21 and pin recess 20-22 are formed on one side of the magnet fixing plate.

Magnet fixing plate 20-2 as set forth above prevents grinding tool 30 falling down on a ground while grinding tool 30 is replaced and prevents dust and impurity produced while the grinding tool is replaced and operated for grinding entering into the inside of the magnet thereby preventing contamination and abrasion and extending the life of the magnet.

Furthermore, in magnet 21 as mounted as set forth above, a fine gap b of FIG. 6 is formed so that the magnet does not directly contact grinding tool 30 and thus impact produced while the grinding operation is performed is not transferred to the magnet thereby increasing efficiency of the magnet.

Tool guide plate 20-3 serves to form tool mounting part 2 and prevent the separation of mounted grinding tool 30, and is mounted on a top surface of magnet fixing plate 20-2 wherein a plurality of tool mounting parts 2 are formed, when required, at an interval such that grinding tool 30 is mounted sequentially at an interval.

As a result, a space adapted to mounting the grinding tool is formed by the top surface of magnet fixing plate 20-2 and the inner side wall of tool mounting part 2 of tool guide plate 20-3. Mounted grinding tool 30 is fixed and located by separation prevention pin 22 of magnet fixing plate 20-2 and kept in place by tool support protrusion 23 of tool guide plate 20-3.

Further, tool guide plate 20-3 has middle hole 20-3 a sized and shaped so that the bottom surface of locking device 5 can be mounted on the top surface of holding protrusion 11. In more detail, tool mounting part 2 has the same shape as main steel plate 33 of grinding tool 30 and further is provided with tool support protrusion 23 to prevent the disengagement of grinding tool 30.

Tool support protrusion 23 protrudes from both ends of the inner wall faces of tool mounting part 2 as a hook shape and prevents the separation of grinding tool 30.

Meanwhile, separation prevention pin 22 provided in the present invention includes middle screw part 22 b screwed to pin recess 20-11 of replacement base plate 20-1, head part 22 c passing through separation prevention pin head hole 12 of mounting wheel plate 10 joined to the lower part of the middle screw part, and support pin part 22 a joined to the upper part of the middle screw part. Support pin part 22 a has a length sufficient to pass through pin recess 20-22 of magnet fixing plate 20-2 and be fitted into pin through hole 32 of grinding tool 30 disposed on tool mounting part 2.

Next, disk-shaped locking device 5 has locking wing 5 a protruding laterally and is provided with middle bolt 5 d in the middle part of the locking device that is fixed to fixing hole 11 c of holding protrusion 11. Locking device 5 further includes catching pin 5 b to be fixed to catching pin fixing hole 11 b and taper recess 5 c for controlling the rotation angle of locking wing 5 a using catching pin 5 b.

The locking wing preferably has an angle of 120° and protrudes in a radial direction. Furthermore, wing mounting part 20-24 on which locking wing 5 a of locking device 5 is mounted as it is rotated protrudes into middle hole 20-2 a of the magnet fixing plate.

The locking device as configured in the forgoing serves to fix replacement wheel plate 20 to mounting wheel plate 10 when required and locking wing 5 a prevents replacement wheel plate 20 being separated while the grinding operation is performed.

Referring to FIGS. 11 and 12, hereinafter, a locking state of the grinding wheel 1 a, that is, the mounting wheel plate 10 and the replacement wheel plate 20 by the locking device 5 will be described.

First, locking device 5 is connected to holding protrusion 11 of the mounting wheel plate 10 by middle bolt 5 d and kept in fixed-connected state rotatably at an arbitrary angle.

As a result, locking wing 5 a of locking device 5 is configured movably depending on the intention of the user. The rotation radius and rotation angle of locking wing 5 a are controlled depending on the size of taper recess 5 c.

Catching pin 5 b is fitted along both end taper surfaces of taper recess 5 c to be fixed thereto so that the locking wing is not separated even due to vibration.

Furthermore, any users may rotate the locking wing 5 a of the locking device 5 for the locking wing 5 a to be mounted on the wing mounting part 20-24 so that replacement wheel plate 20 is not separated downward while replacement wheel plate 20 is fixed over mounting wheel plate 10 for grinding operation.

Replacement wheel plate 20 of grinding wheel 1 a is replaced easily to increase operation efficiency while it is fixed stably to mounting wheel plate 10 by the locking device as configured in the forgoing.

Grinding tool 30 or 30 a may be selected and replaced by a user, according to respective work process in which a grinding operation is performed or a simple gloss operation is performed depending on surface roughness or state of the material to be ground.

FIG. 13 is a view showing a replaceable grinding tool according to the present invention, and as shown in FIG. 13, grinding tool 30 a for a gloss operation has the same size and shape as the whole grinding wheel and further includes Velcro surface 30 a-1 for attaching and detaching replacement grinding tool 30 b on a top surface of grinding tool 30 a.

Furthermore, replacement grinding tool 30 b is provided with tip 31 a for a gloss operation on a top surface thereof and is attached and detached to the Velcro surface of grinding tool 30 a by Velcro surface 30 b-1 formed on a bottom surface of replacement grinding tool 30 b.

Also, a steel plate of a size which is mountable to tool mounting part 2 is provided in order that the grinding tool 30 a can be attached and detached to tool mounting part 2.

When steel plate 33 is mounted to tool mounting part 2, the grinding tool 30 a is located and fixed by the magnet 21 and is attached and detached easily by push injector pin 4 and the recess for pushing.

A plurality of steel plates 33 may be provided to allow easy mounting to tool mounting part 2.

Additionally, the location where the ferromagnetic steel plate is mounted on grinding tool 30 a may be arbitrarily modified, as shown in FIGS. 6-12, to serve as grinding tool 30.

The present invention relates to a grinding wheel assembly for facilitating the attachment and detachment of the grinding tool, and according to the exemplary embodiments of the present invention, the grinding tool is not broken and disengaged during the grinding operation while the grinding tool is replaced easily and promptly through the attachment and detachment way of the grinding tool using a magnet, thereby maximizing operation efficiency compared to the prior art. Furthermore, the grinding tool is not easily moved from its location during the grinding operation due to the separation prevention pin and the tool mounting part and further crack and breakage of the grinding tool can be prevented by efficiently distributing the centrifugal force and frictional force. In addition, the grinding tool is easily separated from the grinding wheel by using the push injector pin configured to push the bottom surface of the grinding tool and the recess for pushing, depending on user's intention, and thus even a beginner can easily replace the grinding tool and the industrial application of the grinding wheel assembly is recognized appropriately.

As set forth above, according to exemplary embodiments of the grinding wheel assembly for facilitating the attachment and detachment of the grinding tool, the grinding tool is not broken and disengaged during the grinding operation while the grinding tool is replaced easily and promptly through the attachment and detachment way of the grinding tool using a magnet thereby maximizing operation efficiency, comparing to the prior art.

Furthermore, the grinding tool is not easily moved from its location during the grinding operation due to the separation prevention pin and the tool mounting part and further crack and breakage of the grinding tool cab be prevented by efficiently distributing the centrifugal force and frictional force.

In addition, the grinding tool is easily separated from the grinding wheel by using the push injector pin configured to push the bottom surface of the grinding tool and the recess for pushing, depending on user's intention, and thus even a beginner can replace easily the grinding tool.

While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims. 

1. A grinding wheel assembly for facilitating an attachment and detachment of a grinding tool, comprising: a grinding tool (30) of ferromagnetic; and a grinding wheel (1 a) of a disk shape, having a tool mounting part (2) which is shaped as a recess sized for the grinding tool (30) to be mounted and into which a magnet (21) is embedded in one side of the inner surface wherein the tool mounting part (2) further comprises a push injector pin (4) that passes through the grinding wheel (1 a) in order to push the bottom surface of the grinding tool (30) mounted in the tool mounting part (2) and separate the grounding wheel from the magnet (21).
 2. The grinding wheel assembly for facilitating an attachment and detachment of a grinding tool of claim 1, wherein the grinding tool (30) is constituted by a steel plate (33) provided with at least one pin through holes (32) in one side thereof and sized to be mounted in the tool mounting part (2), and a grinding tip (31) that is fixed protrudingly over the steel plate (33), and the tool mounting part (2) further comprises a separation prevention pin (22) that is protruded, corresponding to the number and location of the pin through hole (32).
 3. The grinding wheel assembly for facilitating an attachment and detachment of a grinding tool of claim 2, wherein the grinding wheel (1 a) is further provided with a recess for pushing (3) of a concave shape into which the end of the grinding tool (30) is mounted protrudingly along the outer peripheral surface corresponding to the tool mounting part (2) in order to raise the end surface of the grinding tool (30) and separate easily the grinding tool from the magnet (21).
 4. The grinding wheel assembly for facilitating an attachment and detachment of a grinding tool of claim 1, wherein the grinding wheel (1 a) is further provided with a recess for pushing (3) of a concave shape into which the end of the grinding tool (30) is mounted protrudingly along the outer peripheral surface corresponding to the tool mounting part (2) in order to raise the end surface of the grinding tool (30) and separate easily the grinding tool from the magnet (21).
 5. The grinding wheel assembly for facilitating an attachment and detachment of a grinding tool of claim 1, wherein the push injector pin (4) comprises a push bar (4 b) that is movable through the grinding wheel (1 a), a spring (4 a) surrounding the part of the push bar that protrudes to the lower part of the grinding wheel (1 a) and applying elastic force thereto, and a injector pin fixing screw (4 c) for fixing and locating the push bar (4 b) that has passed through the grinding wheel (1 a).
 6. A grinding wheel assembly for facilitating an attachment and detachment of a grinding tool, comprising: a grinding tool (30) of ferromagnetic; and a grinding wheel (1 a) of a disk shape, having a tool mounting part (2) which is shaped as a recess sized for the grinding tool (30) to be mounted and into which a magnet (21) is embedded in one side of the inner surface wherein the grinding wheel (1 a) is constituted by a mounting wheel plate (10) that is fixed to the grinding part and a replacement wheel plate (20) which is sized to be in face-contact with one surface of the mounting wheel plate (10) and mounted thereon, and is attachable and detachable by a locking device (5), and in which the tool mounting part (2) is formed.
 7. A grinding wheel assembly for facilitating an attachment and detachment of a grinding tool of claim. 6, wherein the mounting wheel plate (10) of a disk shape is provided with a holding protrusion (11) that is fixed protrudingly by a fixing bolt (11 a) on a middle part thereof, and a catching pin fixing hole (11 b) that is formed on a top surface of the holding protrusion (11), and a locking device fixing hole (11 c) that is provided on a middle part of the holding protrusion (11).
 8. A grinding wheel assembly for facilitating an attachment and detachment of a grinding tool of claim 7, wherein the replacement wheel plate (20) comprises: a replacement base plate (20-1) of a disk shape which has a middle hole (20-1 a) through which the holding protrusion passes, is in face-contact with one face of the mounting wheel plate (10), and mounted, and in one side of which a pin recess (20-11) through which a separation prevention pin (22) passes is formed; a magnet fixing plate (20-2) of a disk shape which has a middle hole (20-2 a) through which the upper part of the holding protrusion (11) having passed through the replacement base plate (20-1) passes, is in face-contact with another face of the replacement base plate, and is mounted, and in one side of which a pin recess (20-22) through which the upper part of the separation prevention pin (22) having passed through the pin recess (20-11) of the replacement base plate passes and protrudes; and a tool guide plate (20-3) in which a plurality of the tool mounting part (2) are formed at interval, which is mounted on a top surface of the magnet fixing plate (20-2), in which a middle hole (20-3 a) sized for a bottom surface of the locking device (5) to be mounted on a top surface of the holding protrusion (11), and which supports the grinding tool (30) provided in the tool mounting part (2).
 9. A grinding wheel assembly for facilitating an attachment and detachment of a grinding tool of claim 8, wherein the separation prevention pin (22) comprises: a middle screw part (22 b) that is screwed to the pin recess (20-11) of the replacement base plate (20-1); a head part (22 c) that passes through a separation prevention pin head hole (12) of the mounting wheel plate (10) to the lower part of the middle screw part; and a support pin part (22 a) which passes through the pin recess (20-22) of the magnet fixing plate (20-2) to the upper part of the middle screw part and has a length capable of being inserted into the pin through hole (32) of the grinding tool (30) located in the tool mounting part (2).
 10. A grinding wheel assembly for facilitating an attachment and detachment of a grinding tool of claim 8, wherein the locking device (5) of a disk shape is provided with a locking wing (5 a) protruding laterally, a middle bolt (5 d) that is fixed to the holding protrusion (11) locking device fixing hole (11 c) at a center thereof, a catching pin (5 b) that is fixed to a catching pin fixing hole (11 b), and a taper recess (5 c) that controls a rotation angle of the locking wing (5 a) by the catching pin (5 b).
 11. A grinding wheel assembly for facilitating an attachment and detachment of a grinding tool of claim 10, wherein the locking wing has a 120° and protrudes in a radial direction.
 12. A grinding wheel assembly for facilitating an attachment and detachment of a grinding tool of claim 10, wherein a wing mounting part (20-24) to which the locking wing (5 a) of the locking device (5) is mounted according to its rotation is protruded and extended in the middle hole (20-2 a) of the magnet fixing plate. 